Flowering behaviors in annual and perennial fruit crops: A review

Abstract

Flowering is a critical developmental transition in fruit crops that marks the switch from vegetative to reproductive growth of the plant. This transition period ultimately determines the yield potential, fruit quality, and orchard productivity of a crop. Annual fruit crops, such as strawberries, tomatoes, and cucurbits, can bear flowers rapidly after early vegetative growth, relying primarily on short-term environmental cues, including photoperiod, temperature, and nutrient status. In contrast, perennial fruit crops, such as mango, citrus, apple, and grape, follow multi-season flowering cycles regulated by dormancy release, carbohydrate accumulation, shoot maturity, and hormonal balance. Advances over the past two decades have highlighted the central role of FLOWERING LOCUS T (FT) genes, chilling-responsive dormancy-associated MADS-box (DAM) genes, stress-responsive pathways, and hormone interactions with carbohydrates in modulating floral induction across species. This review synthesizes recent knowledge on flowering physiology in annual and perennial fruit crops, emphasizing genetic, hormonal, environmental, and management-related factors that influence flower induction. Special focus is placed on short-day species, such as strawberry and tomatoes, stress-induced flowering in mango and citrus, dormancy-mediated induction in temperate fruits, and alternate bearing patterns. Understanding species-specific flowering controls is vital for improving climate resilience, adapting orchard management, and enhancing sustainable fruit production.